Brainstorm me a disagnostic finding

[Tinster]

I'm a bit over my head on this latest breakdown and
flatbed haul. I'm not sure where to look: A long post.

Facts- Broke down on the side of the expressway, the car
would spin (in neutral) to 4000+ rpms, hold there for
maybe 20 seconds and then sputter, loses rpms, backfires
and dies. To me, it felt like it was running out of fuel.
Not a sudden quit like a cut wire. It was like the bowls
ran dry.

AI DID notice my oil pressure was not the usual 65 psi but
was sitting at about 45 psi. (warm engine) Oil level
checked at full.

Wait a minute or two, the car started, reved easily to 4000+
etc, etc. died. A 3/4 full tank. I drove the car about 70 miles
the day before, ran great up to 75 MPH, parked in the garage.
Next morning an easy start- 3/8 miles and it broke down.
$250. tow charge.

The battery is presently charging since I discharged it pretty
deeply on the expressway.

Friday when it broke down I noticed it was difficult to pull
out the choke knob. With much pull, it would suddenly POP out.
Today in the garage was the same (front carb choke stuck off)
It was stuck so badly the throttle only moved the rear carb
to increase gas flow.

I pulled a few new plugs and they were black as can be. Not normal for my car at all.

I pulled the new fuel filter - clean as a whistle. I saw
no reason (yet) to pull off the carbs and check the float bowls for tank rust.

Brand new condenser can, points clean and not pitted. New
rotor and new dizzy cap. New spark plugs, fuel tank well
vented, new air filters, all new fuel lines, new fuel pump.

Any and all help or suggestions are appreciated,

dale

 

[NickMorgan]

Brain storm.
Plugs show rich mixture.
Backfire points to electrical problem, or certainly not a lack of fuel.
Is your choke sticking on?
HT lead connections all clean?
LT wire connections good - not just the spades, but the connection between the wire and spade?

 

[NickMorgan]

Are all the plugs the same? Compare the front three with the back three to see if one carb is behaving differently from the other.

 

[Guest]

Sounds like a very common rotor burned through and diverting most of the secondary to ground...

 

[poolboy]

Can you disconnect the choke cables from the carbs, push the choke lever arm on the carbs down all the way, into the "off" position and start the engine?

 

[tomshobby]

Remember these three things.
Spark
Fuel
Compression

By eliminating them one by one as a group you can begin to zero in on whatever the problem is instead of guessing at everything at once.

I doubt very much that it is a compression problem so why not eliminate one of the other two.

Dale start with this.
Make sure the problem is acting up so try and start the engine. If it does not start or when it quits then disconnect the fuel line at the carbs and see if it will pump fuel when you spin the engine with the starter.

Next hook up your timing light and turn over the engine while holding the trigger.

At this point you should either have fuel or spark and know which system is the problem.

 

[poolboy]

It might also be a good idea to smell for a gasoline smell in the oil from your dipstick. If there was a problem with the choke flooding the engine, the excess gas might have diluted your motor oil to the point of thinning it and reducing that oil pressure reading.

 

[NickMorgan]

Hang on Dale. In that picture of your carburettors is that the throttle shaft in the left of the picture? Surely it should line up with the other throttle shaft? It looks as though it is quite a long way off. I am not familiar with the TR6 carburettor set up, so maybe someone in the USA can comment.

 

[TR6oldtimer]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Friday when it broke down I noticed it was difficult to pull
out the choke knob. With much pull, it would suddenly POP out.
Today in the garage was the same (front carb choke stuck off)
It was stuck so badly the throttle only moved the rear carb
to increase gas flow.
[/QUOTE]

Dale,
Of all the symptoms you have listed, this is the first time I heard of this one. So I would go through your linkage and chokes to get them to move smoothly and adjusted as designed, if he carbs are not working properly, you are just chasing your tail on the other issues.

 

[Andrew Mace]

Dale, many, many years ago I chased a problem with a TR6 (red, coincidentally!) that would exhibit somewhat similar symptoms. Turned out to be a piece of foil gum wrapper that had been wadded up and dropped into the gas filler. It would often float around but then land itself in such a way to cover the fuel outlet!

Maybe...just maybe...there's a little hunk of something floating around in your tank yet, and it's doing the same thing?

Off-the-wall, I know, but....

 

[martx-5]

Hang on Dale. In that picture of your carburettors is that the throttle shaft in the left of the picture? Surely it should line up with the other throttle shaft? It looks as though it is quite a long way off. I am not familiar with the TR6 carburettor set up, so maybe someone in the USA can comment.

You're absolutely right! There is a big problem there. Somewhere the linkage is binding and most likely caused the accordian link to bend and get out of whack.

Dale, you need to take a few of the links off the carbs and find out where the hang up is. The fact that the choke is a problem to operate is symptomatic of the problem. Start disconnecting the choke cables and the link between the carbs and find out where the hang-up is. You know something is binding, now figure out where it is. Maybe that highly modified heat shield is getting in the way of something.

BTW Nick, I like the way you British folk spell and pronounce "carburettor". I can just see Alain De Cadenet on "Victory by Design" saying "Let's take a look under the bonnet" as he rubs his hands together. "Ah, there they are. Three dual choke Weber carburettors."

 

[NickMorgan]

BTW Nick, I like the way you British folk spell and pronounce "carburettor". I can just see Alain De Cadenet on "Victory by Design" saying "Let's take a look under the bonnet" as he rubs his hands together. "Ah, there they are. Three dual choke Weber carburettors."

Hmm! How do you spell and say it?!

 

[martx-5]

BTW Nick, I like the way you British folk spell and pronounce "carburettor". I can just see Alain De Cadenet on "Victory by Design" saying "Let's take a look under the bonnet" as he rubs his hands together. "Ah, there they are. Three dual choke Weber carburettors."

Hmm! How do you spell and say it?!

We spell it with one "t"...carburetor...pronounced kahr-buh-<span style="font-weight: bold">rey</span>-ter. You guys pronounce it kahr-byuh-<span style="font-weight: bold">ret</span>-er.

 

[Andrew Mace]

...and once again I am reminded of the quote from Dick O'Kane: "Carburetor is a French word meaning 'leave it alone'!"

 

[RonMacPherson]

Cuz,

check your linkage. YOu are describing a slipped, or sticking carb linkage setup. Pictures enclosed by you also indicate this. Take the air filters off and work the throttle by hand(with the engine off naturally) several times to see if the carbs are both moving the same amount, at idle, half throttle and full throttle, correct as necessary. Then focus on the choke linkage, making sure that you have a little tension on the outer choke cable (slight bow in it) before you clip the cable in place...